Korg Electribe EA1 & ER1

In all the fuss about last month's launch of the Triton keyboard, you'd be excused for having overlooked Korg's other new products — the diminutive Electribe EA1 synth and ER1 beatbox. As Chris Carter discovers, however, you won't be able to ignore them for long...

With hi‑tech music products, it often seems there's never a good time to buy, as there will always be something better just around the corner. And if you thought now was a safe time to buy that fab new dance workstation, you may yet have to reconsider, as Korg have decided to add even more choice to an increasingly crowded market. Their latest babies are the Electribes, a two‑voice synthesizer and beatbox based around their physical modelling technology (as seen in the Z1 synth), each incorporating effects, external audio inputs and a pattern‑based sequencer.

Shared Interests

As you can see from the pictures, the two Electribes have a lot in common visually, and much of this similarity extends to their user interfaces, programming method and general layout. In each case there's a large 3‑digit LED which shows the current Pattern or Song you are working within, and is also used to display general housekeeping parameters. These are accessed using a 5x4 parameter matrix to select editable parameters, with data entered using a continuous wheel. Even with such a basic display, there is plenty of visual feedback to help keep track of what's going on, especially since every button illuminates.

Connections abound on both machines, and include audio inputs, a headphone socket, MIDI In, Out and Thru and a socket for a 9V wall‑wart power supply (unfortunately batteries are not an option). The Electribes are approximately 11.5 x 8.5 inches in area and have a very low profile, being only 1.75 inches in depth. They're compact enough to sit on a desktop, next to a turntable or in a DJ bag.

The EA1 contains two independent programmable monosynths, with independent mono outputs and effects, while the ER1 rhythm synth is a 6‑voice stereo beatbox offering two sample‑based voices and four physically modelled ones. Both provide built‑in pattern‑based sequencing along with plentiful helpings of real‑time control, including a Motion Sequencer which allows (some of) your real‑time knob movements to be recorded within a song.

Analogue Model

For now, the ER1 can wait its turn, as I'll start off with a more detailed look at the EA1 Analogue Modelling Synthesizer. In terms of sound generation, the EA1 contains two independent programmable monophonic synthesizers, each of a straightforward two‑oscillator design and combining traditional analogue features such as portamento, oscillator sync, and ring modulation with more unusual features like Decimation (bit reduction) and distortion. The full parameter list for each of the EA1's synths is as follows:

Oscillators

• Osc 1 waveforms: Saw, Pulse, Triangle, External Audio.
• Osc 2 waveforms: Saw, Pulse, Triangle.
• Osc 2 Pitch Offset (variable over four octaves).
• Osc Mod: Ring Mod, Sync, Decimator.
• Osc balance (between 1 & 2).
• • Portamento.

Filter

• Cutoff.
• Resonance.
• EG Density.
• Decay.

Amp

• Level.
• Distortion.

Effects

• Type (Chorus/Flanger, Delay).
• Depth.
• Time (controls chorus/flanger speed).

The synths in the EA1 are based around the analogue modelling technology used in Korg's Z1, and in this incarnation are laid out in a standard VCO‑VCF‑VCA‑EG configuration. As you can see from the features list above, they offer a reasonable arsenal of controls and parameters to play with. The frequency range of the oscillators is wide, though Osc 1's isn't as great as that of Osc 2. Strangely, in their raw state the waveforms all sound vaguely samey: the ring modulator and sync settings, on the other hand, sound as you would expect from an analogue synth, and the Decimator imposes a down‑sampled, grungy edginess to the waveform.

The EA1's two independent monosynths each offer two oscillators, a filter and an effect — but there's no LFO.

The filter is a good approximation of an analogue low‑pass type that sounds more 'Japanese' thanAmerican' (or more Korg/Roland than ARP/Moog). Although it can be persuaded to self‑oscillate, when doing so it displays some uneven peaks and troughs while sweeping. But, all told, not a bad filter.

The envelope control is a bit of a let‑down, though. The Amp section isn't envelope‑controllable at all — it's either on or off — and the filter control is severely limited, offering just an EG Int knob (envelope depth) with a centre null/off position and negative control to the left and positive to the right. This is coupled with a simple Decay control, and although there's no attack control one can be approximated using negative depth values with longer decay settings. Because there is no Amp envelope control, however, there is always a slight blip at the front of the sound.

The EA1's distortion is another on/off effect and works well enough, though it could hardly be described as subtle. There are, however, some redeeming features in the rest of the effects section. The Chorus/Flanger effect is basic, with only two controls, but sounds fine. The Depth parameter both controls the depth of the effect and introduces feedback at the higher settings, while the Time control (or speed in this case) ranges from the very slow to the ridiculously fast (0.2Hz‑5kHz) — which is actually fast enough produce audio‑frequency (and hence audible) oscillation. As you can imagine, at the higher speeds this produces some beautifully crazed and over‑the‑top manipulations.

The other principal effect is Tempo Delay. Again, Depth controls two parameters (delay depth and feedback); with the Time knob set to minimum, the effect is like a flanger, while its maximum setting produces delays of a second or more. As the delay is synchronised to the pattern tempo the delay times will vary in accordance with the pattern speed, so at high tempos the maximum delay available will be shorter than at slower speeds. It's worth noting that because each synth has its own effects section some wonderfully syncopated bouncing echoes can be programmed.

Gripe Water

One gripe I have with many of the synth controls (and this also applies to the effects) is the sensitivity and stability of the knobs. The Osc 2 Pitch Offset is very sensitive, which admittedly makes sweeping the oscillator over four octaves very fast, but also makes it very difficult to fine‑tune. The centre detent stop position rarely settles on the same tuning, sometimes locking on but sometimes gently drifting. The same applies to the Effect Time control: although it was great fun to almost randomly warble the sound at the slightest touch, sometimes I just wanted to set a particular delay time with no hassle.

Something which helps to alleviate this pet peeve of mine, though, is a useful feature called Original Value. This is just a single LED that glows whenever a control you are editing settles on its previously programmed value, which is useful if you are trying to go back a few editing stages without actually reloading a whole sound. Original Value works on all the knobs until you save the current settings to memory.

All synth settings are saved as a pair (Part 1&2) within an associated pattern: the pattern doesn't have to contain any sequenced notes, but all patterns will contain synth setting information and Parts can be freely copied and exchanged with other Patterns.

Vintage Model

It may not be a Minimoog or SH101, but the EA1 can still hold its own in company. Including not only two oscillators per synth but two synths, and some interesting modulation options into the bargain, is pure genius and makes up for some of the EA1's shortcomings. Coupled with the effects, the overall combination is very versatile and quite powerful. This is shown in some of the presets, which include some wonderfully deep and powerful bass lines and all manner of weird, wonderful and wacky synth tones and patterns. Hand on heart I couldn't say the EA1 is absolutely 'vintage', but it's definitely close to the cutting edge.

Horror of horrors, though, there's no LFO modulation for the oscillators, not even over MIDI — maybe that's to come in the EA1 Mk2...

Pattern Sequencing

The 16 illuminated rubber buttons along the front are used for playing the synth voices (when this mode is activated using the Keyboard button) and also for editing, selecting, moving and deleting Parts, Patterns, Events and Songs. There are also two Transpose buttons that allow you to transpose individual notes across six octaves.

Patterns can be as short as 12 steps or as long as 64, and can be in 4/4, 3/4 or triplet timing. In Step Edit mode there are options for adjusting note Pitch and Gate times and inserting Rests and Ties, though there's no option for velocity control. When the sequencer is running the 16 keyboard buttons light up to show which notes in the selected Part are playing, providing a useful guide when editing individual notes within a pattern.

The sequencer section defaults to real‑time loop recording mode and is easy to use in the extreme. Pressing the Record button (the large one on the left‑hand side) makes it glows red, puts everything into record standby mode, and sets the Play/Pause button flashing green. Press the Play/Pause button and real‑time looped recording begins. You now play your notes using the keyboard buttons (or external MIDI keyboard).

As you play, you can switch back and forth between the two synths, hold down the erase button and relevant note to delete bum notes and mistakes, and even engage the Motion Sequence feature and record a little knob‑twiddling at the same time. The Motion Sequencer is an adaptation of a feature I first came across in Boss's DR202 Dr. Groove drum machine, and in the Dr. Groove you could record most of the knomovements within a pattern. With the EA1, however, you can only record a single knob or button activity for each synth voice. Once you've recorded your knob movements there are two playback options: Smooth plays back pretty much what you recorded, while TrigHold quantises the motion to the nearest 16th beat.

Steps

Song construction is also a straightforward affair. There are two input options: Step programming and Event programming. Step mode is just a matter of assembling a song by selecting the appropriate pattern at each step until you have assembled your complete song. Once you've assembled a Song there are editing options for Inserting, Deleting and Transposing Patterns.

Alternatively, Event mode is supposed to allow real‑time recording of the Keyboard buttons into a song, but the results aren't very rewarding. There is a small warning in the instruction manual that states: "After rewinding a song it may not be possible to play back exactly according to the event data." You're not kidding, mate! It sounds rubbish, and it wasn't my style of playing either. My advice is to stick with the default Step mode.

A Suitable Case For Treatment

A feature that fell out of favour for years but is now being introduced on many new synths is an external audio input, and it was a pleasant surprise to find one included on the EA1. The external source needs to be at line level to get the best use of this feature, and once inside the EA1 the sound can be treated just like the oscillator waveforms. The Ring Modulator, Decimator, Distortion, Filter and Effects are all available for treating the external sound. Not only that but you can set up entirely different sets of treatments for each part, simultaneously.

MIDI Spec

The EA1 has a reasonable MIDI specification, and external MIDI control is available for most of the EA1's parameters including saving and loading patterns and songs, MIDI sync (master or slave), selecting patterns and songs remotely, and individual MIDI keyboard or sequencer control of the synths. The EA1 will respond to pitch‑bend data but it won't recognise velocity or modulation. Real‑time parameter tweaks can be transmitted over MIDI as NRPNs, and edited in a sequencer such as Cubase, though as with the built‑in Motion Sequencer only one parameter can be recorded for each synth. A nice touch is that the Keyboard buttons light up in response to incoming MIDI notes.

Other features are the familiar Tap Tempo, which is no worse (or particularly better) than most other beatbox versions I've tried, and Pattern Set. The latter is useful in that it allows you to assign 16 of your favourite patterns/synths to the 16 Keyboard buttons for instant access, and is a great feature for jamming or live playing.

Korg ER1 Rhythm Synthesizer

As I've said above, there are many similarities between the two Electribes, and some of the features and functionality of the EA1 I've covered also apply to the ER1. For instance, setting system modes, using and editing parameters with the parameter grid and the 16 pattern buttons (ie. editing, deleting, copying and patterns, pattern scale, swing setting and pattern step number and so on), MIDI functions and using Song mode (recording and playing back) are all fundamentally the same on both units. So if you are using both units, this makes the learning curve a lot easier, and also comes in handy when using the Electribes side by side (particularly if they are sync'ed via MIDI) as you tend to operate them as a single workstation.

The ER1 is a 6‑voice programmable beatbox, unashamedly in the vintage Roland TR style — maybe not in appearance, but definitely in concept and execution. Unusually, the percussion sounds are constructed from four programmable oscillators and four adjustable percussion samples (open/closed hi‑hat, crash and clap). There are also two audio inputs which can be integrated into rhythm pattern steps and processed like the other percussion voices. Rhythms are constructed using the now‑classic Roland‑style step programming method (as used on the TR707, 808, and 909). The ER1 comes with 192 preset patterns, and users can overwrite these with 256 of their own making.

Each of the four percussion oscillators has the following controls (see diagram):

• Pitch: 20Hz‑12kHz.
• Wave: Sine or Triangle.
• Mod Depth: +/‑ 0 to 100%.
• Mod Speed: 0.1Hz — 5kHz.
• Mod Type: Saw, Square, Triangle, Random, Noise, Envelope.

In addition, every voice (this includes the oscillators, PCM samples and external inputs) also has Decay, Level, Pan and a Low Boost control. The Low Boost introduces a pleasant bass distortion and really does what it says, with a vengeance, so be careful with your speakers — particularly if you're using it on more than one percussion sound.

The ER1's analogue modelled percussion voices offer a wide range of control over the sound.

A further sound‑modifying feature is the inclusion of two ring modulators. One works in conjunction with oscillators 1 and 2, while the other works with oscillator 4 and either of the external audio inputs. As with all ring modulators, two sounds have to be present simultaneously for any sound to be heard. This means any voices to be ring‑modulated have to be on the same pattern step number, or you'll just hear the sound of silence. When used with an external audio input, therefore, you'll need to keep the flow of sound constant to get results (which, by the way, are very good).

Whereas the EA1 essentially operates as two independent synths, each with its own mono output, the ER1 is a stereo unit, hence the presence of voice pan controls and ping‑pong type stereo delays.

Edit Suite

Instead of the single Part Select button of the EA1, the ER1 has a Part Select bank of 13 buttons — 10 for selecting voices, two for the Ring Modulators and one for the Accent feature. As only one voice button is ever active, you can see at a glance which voice is currently being edited or available for placing into a rhythm pattern.

Each of the four PCM samples can be transposed over a wide range using the Pitch knob and further modified using the Decay and Low Boost controls, but only two samples can sound at once. To be honest, I could do without the rather lacklustre samples (which all sound like they were taken from an ancient TR909) and would rather have a couple more oscillators to play with, because the range of sounds available from the percussion oscillators is truly astounding. Even with only four oscillators, some incredibly complex and unique‑sounding patterns can be built up, like nothing you've heard before.

Some of this sonic flexibility can be attributed to the slightly different implementation of the Motion Sequencer in the ER1 (of which more later), but the almost infinite modulation and pitch‑warping possibilities available to the percussion oscillators outshine the oscillators in the totally non‑LFO‑equipped EA1 by miles. Sure, you can simulate run‑of‑the‑mill analogue kick drums, snares, toms and hi‑hats, but the ER1 really shines when it's making none of these bog‑standard drum sounds.

Patterns

Pattern recording will be familiar territory to anyone who's used a Roland TR drum machine, Steinberg's Rebirth, or anything that uses the standard step‑time method. Step‑time is the default recording mode, and is always active in Play, Pause and Stop modes. As with the EA1, you can set the number of steps from 12 to 64, and the time signature can be 4/4, 3/4 or 4/4 with triplets.

To record a pattern you just select a voice (using the Part Select bank) and tap a few of the Pattern buttons, which now glow steadily; if a rhythm is playing you see the familiar 808/909‑style running LED display along the Pattern buttons. Add more voices or steps as you go along and build up a rhythm — and that's it! Song construction is the same as on the EA1.

The ER1's Motion Sequencer works in a slightly different manner to that of the EA1 (and is, I would say, an improvement on it). The global stereo Delay effect is essentially the same as the EA1's mono versions and can produce the same type of wacky flange‑y effects. It has two parameters: Tempo (synchronised to the song's tempo) and Motion Seq; in the ER1, however, the delay effect has a dedicated Motion Sequencer for each pattern. In addition, all the voices have their own Motion Sequencer, which can record knob movements for any of the controls associated with a particular voice — now that's more like it!

With this much control at your fingertips you can of course go completely over the top if you wish, sweeping the pitch of every oscillator and sample throughout a pattern. There's a very useful Part Solo/Part Mute feature for isolating or muting individual voices (playing or paused) and, interestingly, I found that the ER1's voices respond to velocity over MIDI. Quite why the EA1's don't I'm not sure, but they ought to.

Are These Tribes Worth Fighting For?

Both Electribes are capable of some very unusual, wide‑ranging sounds. The ER1 comes across as particularly radical, almost anarchic at times. Some of the uniqueness of the Electribes can be attributed to the unusual implementation of the delay effects and Motion Sequencer — using both these features together can create some truly Frankenstein‑like warping of sounds and patterns.

In some respects, each Electribe is missing features that the other would benefit from. The brilliant LFO modulation feature of the ER1 would work wonders with the EA1's oscillators — I'm still totally mystified why the EA1 doesn't have this most basic of synth tools — while the ER1 could use another effect or two. To some extent the Electribes buck the trend of hundreds of formulaic preset dance styles, patterns and sounds, and there's certainly no sign of GM either. The presets are all erasable — which, if anything, encourages the user to experiment with new sounds and patterns of their own. And although the supplied preset patterns are on the whole perfectly usable and sound very polished and professional, I suspect (and hope) that a lot of users will be diving headlong into the murky waters of hands‑on programming and coming up with their own unique sounds and rhythms.

The DIY approach to making percussion sounds and easy‑to‑use step‑style rhythm construction of the ER1, plus the EA1's new spin on vintage‑flavour analogue modelling, makes for a couple of tasty packages, and cheap to boot. There's little direct competition to the Electribes in this price range, especially taking into account the sounds they're capable of producing. In this respect they may not be to everyone's taste, because particularly with the EA1 it is almost too easy to produce wonderfully formless, atonal chaos, totally lacking in rhythm (mmm... lovely). Frequently, it takes a while for something as radical‑sounding as the Electribes to make an impression. But they will: nothing this good will go unnoticed for very long.

Apart from a few points I've mentioned above, there's very little to complain about in the Korg Electribes. My personal favourite is probably the ER1 Rhythm Synth and I'm up for buying one as soon as I feel flush. But it's a close‑run race: they're both versatile, both sound bloody great, they're easy to use and they're cheap — what more could you ask for?